The present invention relates to a socket for an electronic part and, more particularly, to a socket adapted designed so that an electronic part such as a CPU or an MPU is pushed into and received in a socket body to maintain contact of the electrode terminals of the electronic part with the electrode portions of the socket body.
In recent years, electronic part having a large number of electrode terminals such as a CPU or an MPU has been equipped with pin-grid array electrode terminals or cheaper electrode terminals such as ball-grid array electrode terminals and land-grid array electrode terminals. A socket for use with such an electronic part having these electrode terminals is used to mount this electronic part on a printed wiring board and to make electrical connection of the electrode terminals of the electronic part with the circuit of the printed wiring board.
A known socket of this kind for an electronic part has a socket body into which the electronic part is pushed, for maintaining connection of the electrode terminals of the electronic part with the electrode terminals of the socket body. Further concretely, the socket body has one end portion coupled to one end portion of a push member with a hinge member. The push member is swung about the coupled position. After the push member has been urged into the socket body side, a hook which acts as a latch mechanism capable of opening and closing and is mounted to the other end of the push member is engaged on an engaging portion of the socket body. Thus, the electronic part is fixedly mounted to the socket body. The contact of the electrode terminals of the electronic part with the electrode terminals of the socket body is maintained. The use of this kind of socket for the electronic part has a merit in that it facilitates attaching and detaching of the electronic part and its maintenance or the like, unlike the case where electrode terminals are soldered together by a reflow or the like.
The individual electrodes of the electronic part and of the socket body differ from each other due to their materials and fabrication processes. Further, in the electronic part having plural electrode terminals and in the socket body, the surface holding the electrode terminals has a certain area. Therefore, there is the possibility that the load of the push member forced against the socket body is imposed nonuniformly among the plural electrode terminals. These differences and nonuniform application of the load would normally induce poor contact of the electronic part with the socket body. To prevent this, a socket is used which renders movable a terminal member which makes contact with the electrode terminals of the electronic part.
However, it has been found that this socket for an electronic part cannot readily satisfy the following two requirements (1) and (2) simultaneously: (1) when the socket is placed in position, the movable contact member reliably makes contact with a support member, and (2) the movable contact member easily returns to a protruding position. Furthermore, it has been found that this socket becomes complex in structure.